Communication of audio signals plays an important role in radio and TV broadcast. With the advent of digital technology, terrestrial and satellite digital audio broadcast (DAB) systems have been proposed. In prior art, to efficiently utilize transmission bandwidth to communicate audio signals, a perceptual audio coding (PAC) technique is often employed. For details on the PAC technique, one may refer to U.S. Pat. No. 5,285,498 issued Feb. 8, 1994 to Johnston; and U.S. Pat. No. 5,040,217 issued Aug. 13, 1991 to Brandenburg et al., both of which are hereby incorporated by reference. In accordance with such a PAC technique, each of a succession of time domain blocks of an audio signal representing audio information is coded in the frequency domain. Specifically, the frequency domain representation of each block is divided into coder bands, each of which is individually coded, based on psycho-acoustic criteria, in such a way that the audio information is significantly compressed, thereby requiring a smaller number of bits to represent the audio information than would be the case if the audio information were represented in a more simplistic digital format, such as the PCM format.
In many broadcast systems including the aforementioned DAB systems, it is possible to transmit audio signals over multiple alternative channels, which are simultaneously available for signal transmission. In prior art, in anticipation of a loss or significant degradation of a transmitted signal because of imperfect channel conditions, multiple alternative channels are typically used to transmit duplicate signals, respectively, to realize path diversity, thereby improving the accuracy of recovery of the transmitted signal. An example for a realization of path diversity may be broadcasting duplicate digital audio signals via multiple satellites in a satellite DAB system.